View Full Version : Polyurethane coating on inside of SRX

04-29-2003, 12:08 AM
Can Gene or any of the other Pearl reps tell me if any coats of urethane are applied to the inside of the SRX shells (if any)?

How many on the outside?

I ask because my old MLX appeared to have a mutiple coatings on the inside and several coatings on the outside. Is the urethane applied to the inside of shells to affect sonic properties only or to protect the shells from humidity/moisture absorption or both.
Would it be worthwhile to increase or apply a coat of urethane to the inside of an SRX kit to protect shells against moisture absorption which might cause swelling, splitting etc.? Or would this do more harm than good?
If this sounds like a reasonable precaution to take would it be better to use a water based or oil based urethane? What about a wood wax?

The Swish Knocker
04-29-2003, 08:28 AM
I was thinking that polyurethane was the stuff they put on all the drums to make them flame retardant, but i just asked my physics teacher ans she says that polyurethane is flammable. So I'm sure this probably didn't help at all.

04-29-2003, 12:05 PM
Polyurethane is placed on the outside of the drums to protect the wood and finish from moisture, stains, dirt. Its easy to clean and repair when damaged.. Its what they use on hardwood floors. In its liquid form it is flammable but not highly flammable like gasoline or say kerosene. When hardened it is no more flammable or at least not that much more flammable than the wood it is applied to.

04-30-2003, 11:34 AM
As far as I have heard Gene say, and saw for my self first hand, the inner part of the shells are "dusted" or applied a very thin coat, which is evident especially on Maple shells as they will appear to be a nice rich dark color compared to some other company's maple, especially if you remove a lug and look at the shell color between the outer and inner ply, you will be able to see it. He says they do this for, well here's Gene:
Originally posted by Gene Okamoto:

2) Pearl drums are dusted with a sealer to prevent moisture from entering the shells. But even without the sealer our shells are highly moisture resistant. During the forming process, our molds are heated to the boiling point of the glue. Then the shells are compressed under 1000 pounds per square inch pressure. The combined effect literally boils and compresses the glue into every pore of the wood for thorough shell adhesion and moisture resistance…”where the glue is, moisture isn’t.” As a matter of fact, the world record for underwater drumming was set on a Pearl BLX kit in 1992 in Rotterdam, Holland. After the event, the kit was fished out and dried and is still in perfect condition and in use today. If Pearl drums can withstand this kind of extreme exposure to moisture imagine what how they can hold up under normal use!

3) Yes, all Pearl drums are sanded smooth on the inside.

Thanks, Gene. That exerpt is from this thread- (http://)